3D-Printed OMFC-supercapacitor hybrids for sustainable energy recovery

Over the past 14 years, osmotic microbial fuel cell (OMFC) technology has been applied in the purification of drinking water, bioenergy production, environmental monitoring and resource recovery at the bench scale. However, it still faces significant challenges in industrial implementation and scaling towards commercialization. These challenges include complex reactor design for handling high reaction volume, long start-up time, costly and laborious fabrication processes for large-scale systems. Interestingly, to overcome these challenges, incorporating 3-dimensional printing (3DP) technology with OMFC seems a viable and promising approach. Furthermore, 3D-printed bio-anodes could offer quick start-up in the current generation using OMFC without any time lags. Also, a stacked OMFC-coupled supercapacitor (SC) system can be easily designed using 3DP technology to generate and store a significant amount of bioelectricity and produce pure water from wastewater. To the best of the author's knowledge, this is the first review paper that specifically highlights the application of 3DP in developing a stacked OMFC system coupled with SC to harvest and store a significant amount of bioenergy in the form of electricity. Similarly, one noteworthy aspect of 3DP technology is its consistent production capabilities, that allow OMFC systems to be scaled up by building multiple stacks of OMFC units without wasting materials and completely free from human error. This review further aims to present the current state and status of the 3DP application to advance OMFC-SC and explore potential future applications of it along with global energy demand.